Wally wrote:
Been on the allotment today and pulled a
few sticks of rhubarb, cut off the leaves and
threw onto the compost heap.
I have since been told that I shouldn't compost
the leaves as they are poisonous.
Other allotment holders have said that it will not
cause a problem.

I've been composting ours, having read (either here on a link posted here
previously) that they aer ok to compost.
(but yes, they are poisonous. Don't feed them to your pet rabbit, or put
them in a salad - as a German friend's mum apparently does!)